This invention relates to the processing of semiconductor dies or wafers and more particularly to the stabilization, passivation or corrosion protection thereof.
The operating characteristics of a semiconductor device must remain relatively stable throughout its life. Typically, planar silicon devices have been stabilized by growing a passivating layer, such as silicon dioxide, on the surface of the body of semiconductor material, whereat the PN junctions terminate. Such passivating layers substantially improve the performance of the semiconductor device. The stability of the operating characteristics of the devices are also known to be further improved by diffusing beneficial impurities into the semiconductor material and its passivating layer.
Another form of passivation is a vapor deposited glass containing such a beneficial impurity as is disclosed in U.S. Pat. No. 3,476,619, assigned to the same assignee as herein. Such a chemically deposited glass requires processing at relatively high temperatures in controlled gaseous environments. For example, in accordance with the foregoing patent, a wafer is held at a temperature of 425.degree.C - 450.degree.C while a gaseous mixture containing phosphine, silane and oxygen is passed thereover.